4 in 1 CO2 Diffuser: This is a high performance 4 in 1 CO2 diffuser for DIY CO2 (1-2 bar) and compressed CO2 systems for 300 liter aquarium. /li>Multi-function: These CO2 foggers have a built-in multi-function system, including check valve, bubble counter, ultrasonic spray and U-shaped air inlet. is also included for mounting.Easy Installation: This diffuser is easy to install. A suction cup for mounting is also included.Low Cost: This CO2 system is designed for economical use in planted tanks.Guarantee: 100% money back or if there is a problem.Product Description This is a high performance 4 in 1 CO2 diffuser for DIY CO2 system (1-2 bar) and compressed CO2 system for 300 liter aquarium. . This CO2 fogger with multi-functional integrated all-in-one system features check valve, bubble counter, ultra microporous spray and U-shaped air inlet. The suction cup is also included for mounting. Contents : . 1 CO2 diffuser 4 in 1.